Cadmium is an environmental pollutant which has been shown to be toxic to a number of tissues in mammalian systems. The present studies are designed to determine factors important in the distribution and excretion of cadmium. Information will be obtained on factors that increase the amount of metallothionein and the overall importance of metallothionein, not only on the distribution and excretion of cadmium but also if it may play a role in the detoxification of other xenobiotics. The toxicological significance of a different distribution of cadmium to a number of target organs in newborns compared to adult rats will also be investigated. The cellular mechanism for cadmium toxicity will be investigated as well as the ability of various chelators to increase the excretion of cadmium and decrease its toxicity.